Clinical Evaluation of Commercial HARDSON COVID-19 Antigen Rapid Test Kit for Routine COVID-19 Diagnosis

Objective

This study aimed to evaluate the sensitivity, specificity, and accuracy of the commercial HARDSON COVID-19 Antigen Rapid Test Kit for diagnosing COVID-19 among the Iranian population by compared with the results of commercial RT-PCR.

Materials and Methods

Two nasopharyngeal swabs were collected from each patient. One swab was tested with HARDSON COVID-19 Antigen Rapid Test Kit, and the second swab was placed in 3 mL of a virus-transmitted inactivated media for RT-PCR testing. Then, the results of both tests were compared to investigate the diagnostic accuracy of the rapid antigen test.

Results

A total of 275 suspected COVID-19 patients' samples were collected to investigate the diagnostic accuracy of HARDSON COVID-19 Antigen Rapid Test Kit. In this study, 162 positive and 113 negative samples were evaluated. As a result, the sensitivity, specificity, and accuracy of HARDSON COVID-19 Antigen Rapid Test Kit were 90%, 100%, and 94%, respectively.

Conclusion

The diagnostic kit analyzed in this study indicated excellent specificity and a relatively good overall sensitivity for the diagnosis of COVID-19 when compared with the RT-PCR detection kit. Based on the result of this study, COVID-19 Antigen Rapid Test Kit indicated a good sensitivity (96%) in low cycle threshold (Ct) value, and it would be recommended to be integrated into routine diagnostic laboratories and used as an at-home rapid antigen test.

Retrospective and Comparative Study of Three Molecular Assays for the Macrolide Resistance Detection in Mycoplasma genitalium Positive Urogenital Specimens

The capacity of Mycoplasma genitalium to develop resistance to macrolides makes detection of macrolide resistance genes by rapid real-time PCR assays increasingly necessary in clinical diagnostic laboratories so as to initiate appropriate treatment as rapidly as possible. The aim of this retrospective and comparative study was to conduct the clinical evaluation of three commercially available kits for macrolide resistance detection. A total of 111 M. genitalium positive samples analyzed in the Clinical Microbiology Laboratory of the Miguel Servet University Hospital, Zaragoza (Spain) were used. After M. genitalium molecular confirmation, the three assays under study were evaluated and discrepant results were resolved via sequencing. The clinical sensitivity for resistance detection was 83% (95% confidence interval, 69% to 93%) for the ResistancePlus^® MG panel kit (SpeeDx Pty Ltd., Sydney, Australia), 95% (84% to 99%) for Allplex^TM MG & AziR Assay (Seegene^®, Seoul, Korea), and 97% (88% to 99%) for the VIASURE macrolide resistance-associated mutations (23SrRNA) Real time PCR detection kit (Certest Biotec, Zaragoza, Spain). The clinical specificity was 100% (94% to 100%) for Allplex and VIASURE assays and 95% (86% to 99%) for SpeeDx assay. The results arising from this study are cause for strong consideration for the implementation of rapid real-time PCR assays in clinical diagnosis laboratories to eliminate treatment failure and transmission as soon as possible.

Antimicrobial susceptibility testing: An updated primer for clinicians in the era of antimicrobial resistance: Insights from the Society of Infectious Diseases Pharmacists

Antimicrobial susceptibility testing (AST) is a critical function of the clinical microbiology laboratory and is essential for optimizing care of patients with infectious diseases, monitoring antimicrobial resistance (AMR) trends, and informing public health initiatives. Several methods are available for performing AST including broth microdilution, agar dilution, and disk diffusion. Technological advances such as the development of commercial automated susceptibility testing platforms and the advent of rapid diagnostic tests have improved the rapidity, robustness, and clinical application of AST. Numerous accrediting and regulatory agencies are involved in the process of AST and setting and revising breakpoints, including the U.S. Food and Drug Administration and the Clinical and Laboratory Standards Institute. Challenges to optimizing AST include the emergence of new resistance mechanisms, the development of new antimicrobial agents, and generation of new data requiring updates and revisions to established methods and breakpoints. Together, the challenges in AST methods and their interpretation create important opportunities for well-informed clinicians to improve patient outcomes and provide value to antimicrobial stewardship programs, especially in the setting of rapidly changing and increasing AMR. Addressing AST challenges will involve continued development of new technologies along with collaboration between clinicians and the laboratory to facilitate optimal antimicrobial use, combat the increasing burden of AMR, and inform the development of novel antimicrobials. This updated primer serves to reinforce important principles of AST, and to provide guidance on their implementation and optimization.

Comparison of the BioFire Joint Infection Panel to 16S Ribosomal RNA Gene-Based Targeted Metagenomic Sequencing for Testing Synovial Fluid from Patients with Knee Arthroplasty Failure

The diagnosis of periprosthetic joint infection (PJI) is challenging, often requiring multiple clinical specimens and diagnostic techniques, some with prolonged result turnaround times. Here, the diagnostic performance of the Investigational Use Only (IUO) BioFire Joint Infection (JI) Panel was compared to 16S rRNA gene-based targeted metagenomic sequencing (tMGS) applied to synovial fluid for PJI diagnosis. Sixty synovial fluid samples from knee arthroplasty failure archived at -80°C were tested. Infectious Diseases Society of America (IDSA) diagnostic criteria were used to classify PJI. For culture-positive PJI with pathogens targeted by the JI panel, JI panel sensitivity was 91% (21/23; 95% confidence interval [CI], 73 to 98%), and tMGS sensitivity was 96% (23/24; 95% CI, 80 to 99%) (P = 0.56). Overall sensitivities of the JI panel and tMGS for PJI diagnosis were 56% (24/43; 95% CI, 41 to 70%) and 93% (41/44; 95% CI, 82 to 98%), respectively (P < 0.001). JI panel and tMGS overall specificities were 100% (16/16; 95% CI, 81 to 100%) and 94% (15/16; 95% CI, 72 to 99%), respectively. While the clinical sensitivity of the JI panel was excellent for on-panel microorganisms, overall sensitivity for PJI diagnosis was low due to the absence of Staphylococcus epidermidis, a common causative pathogen of PJI, on the panel. A PJI diagnostic algorithm for the use of both molecular tests is proposed.

Bursaphelenchus xylophilus detection and analysis system based on CRISPR - Cas12

Pine wilt disease is caused by the pine wood nematode (Bursaphelenchus xylophilus) and leads to wilting and death of pines. It is one of the most damaging diseases of pines worldwide. Therefore, accurate and rapid detection methods are of great importance for the control of B. xylophilus. Traditional detection methods have some problems, such as being time-consuming and requiring expensive instruments. In this study, the loop-mediated isothermal amplification (LAMP) and clustered regularly interspaced short palindromic repeats (CRISPR) were used to establish a set of intelligent detection and analysis system for B. xylophilus, called LAMP-CRISPR/Cas12a analysis, which integrated field sampling, rapid detection and intelligent control analysis. The process can be completed within 1 hour, from sample pretreatment and detection to data analysis. Compared with the single LAMP method, the LAMP-CRISPR/Cas12a assay uses species-specific fluorescence cleavage to detect target amplicons. This process confirms the amplicon identity, thereby avoiding false-positive results from non-specific amplicons, and the large amounts of irrelevant background DNA do not interfere with the reaction. The LAMP-CRISPR/Cas12a assay was applied to 46 pine wood samples and the samples carrying B. xylophilus nematodes were successfully identified. To meet the needs of different environments, we designed three methods to interpret the data: 1) naked eye interpretation; 2) lateral flow biosensor assay; and 3) integrated molecular analysis system to standardize and intellectualize the detection process. Application of the B. xylophilus detection and analysis system will reduce the professional and technical requirements for the operating environment and operators and help to ensure the accuracy of the detection results, which is important in grass-root B. xylophilus detection institutions.

The Influence of Preforming Protein Coronas on the Performance of Dengue NS1 Immunoassays

The effect of preformed protein coronas on immunoassays for Dengue nonstructural protein 1 (NS1) immunoassays was investigated. The composition of the protein corona that forms around nanoparticle-antibody conjugates in human serum was characterized, and selected proteins from the corona were used for preformed coronas (human serum albumin and apolipoprotein A1). Coronas were formed and characterized by dynamic light scattering (DLS), and the nanoparticle-conjugate was probed by optical absorption spectroscopy. Immunoassays were run, and performance was quantified by analyzing the strip intensity as a function of NS1 concentration. The preformed coronas influenced the limit of detection (LOD) of the assay and the affinity for the NS1 target (KD). The resulting KD and LODs for the NP-Ab-ApoA1 immunoprobes were 0.83 nM and 1.24 nM, respectively. For the NP-Ab -HSA coronas, the test line intensity was lower by 33% at a given NS1 concentration than for the NP-Ab immunoprobes, and KD was 0.14 nM, a slightly higher affinity. Due to the relatively large error of the negative control, a meaningful LOD for the NP-Ab with HSA coronas could not be determined.

Immunogenicity Response of Mus musculus var. Balb/C after Immunization using Flagellin Salmonella typhi Serovar Semarang

&lt;b&gt;Background and Objective:&lt;/b&gt; The flagellin of &lt;i&gt;Salmonella typhi&lt;/i&gt; is potentially developed as an identifying antigen in a rapid diagnostic test instrument that may be more accurate than conventional serological tests. Therefore, this study aims to analyze the immunogenicity of flagellin &lt;i&gt;S. typhi&lt;/i&gt; as the basis for developing a typhoid fever diagnostic. &lt;b&gt;Materials and Methods:&lt;/b&gt; Flagellin was isolated from the bacterial culture of &lt;i&gt;S. typhi&lt;/i&gt; serovar Semarang and used as the primary antigen for vaccine assembly. Native flagellin antigen was immunized in Balb/C mice with injection doses of 2, 3, 4, 5 and 6 g/100 L in each group (K0-K5), respectively, via intraperitoneal cavity. Blood serum was collected to ELISA based-measurement for IL-6 and TNF-a titers. Then, specific immunoglobulin (Ig) of anti-flagellin was detected using in-house ELISA and western blotting. &lt;b&gt;Results:&lt;/b&gt; The findings in this study showed that immunization at the dose of 4-5 g/100 L significantly decreased the IL-6 titer, i.e., 8.33±0.87 pg mL&lt;sup&gt;1&lt;/sup&gt;, compared to control. The antibody titer test analysis showed the highest Ig-G anti-flagellin was found in K4 mice after immunization using a dose of 5 g/100 L with an average absorbance of Ig-G reaching 1.19 ±0.32. &lt;b&gt;Conclusion:&lt;/b&gt; The results indicated that the flagellin protein of &lt;i&gt;S. typhi&lt;/i&gt; serovar Semarang induces adaptive immune responses and produces specific antibodies against flagellin. The immunogenic properties of the flagellin protein of &lt;i&gt;S. typhi&lt;/i&gt; serovar Semarang potentially developed as a specific diagnostic marker. Further research may also focus on a beneficial feature of flagellin as a vaccine candidate.

Comparison of different rapid screening tests and ELISA for HBV, HCV, and HIV among healthy blood donors and recipients at Jibla University Hospital Yemen

Blood transfusion is associated with many risks, especially exposure to blood transfusion-transmitted infections considered one of the main causes of death worldwide, including hepatitis B (HBV) and C virus (HCV) and human immunodeficiency virus (HIV). The threat posed by blood-borne pathogens is disproportionately high, especially in developing countries, so there is a need for continuous monitoring of blood transfusions to prevent transmitting diseases. Rapid diagnostic immunochromatographic technique (ICT) methods are the most widely used methods in developing countries, although ELISA and molecular testing are considered more accurate worldwide. Therefore, the study aimed to compare the analytical sensitivity between rapid tests and the ELISA method for detecting HBV, HCV, and HIV infection among blood donors. Four hundred (400) blood donor samples were tested using the Rapid Test Kits (INTEC, SD, ABON, and CLUN), and the ELISA method was used as a confirmatory test. Out of 400 blood samples tested for viral infection, HBV, HCV, and HIV were detected in 8, 10, and 2 samples, respectively, using the ELISA technique. This study observed that the rate of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), in addition to determining the diagnostic accuracy rate and error rate for all rapid diagnostic kits in detecting HBV, HCV and HIV are less accurate and associated with more false negatives compared to the ELISA technique. This study showed a significant difference in sensitivity between ELISA and rapid diagnostic immunochromatographic technique (ICT) groups; therefore, rapid diagnosis is not suitable for testing the quality of infectious markers for blood donors.

Chemotherapy-Induced, Broadly Reactive Autoantibodies in a Colon Cancer Patient

The link between cancer and autoimmunity is well-established. For example, increased levels of autoantibodies are frequently found in cancer patients, and autoimmune diseases are linked to an increased risk for certain neoplasms. However, the extent to which chemotherapy induces autoimmune reactions remains largely elusive. Here, we quantified immunoglobulin M (IgM) responses to various human tissues and the patient's tumor before and during adjuvanted chemotherapy (seven cycles of the FOLFIRI regimen (folinic acid/fluorouracil/irinotecan) plus cetuximab) of a patient with metastasized colon cancer. IgM levels against all investigated tissues increased shortly after the first cycle and were further boosted by cycles two and three. Autoimmune responses then decreased during cycles four to seven but remained above baseline levels for most tissues. Our findings suggest that chemotherapy can induce broadly reactive autoimmune responses. Monitoring self-reactive IgM responses during treatment may help alleviate autoimmunity-related adverse events.

Development of a recombinase polymerase amplification assay for viral haemorrhagic septicemia virus

Viral diseases of fish cause significant economic losses in the aquaculture industry. Viral haemorrhagic septicemia virus (VHSV) is one of the most important viral diseases that affects more than 80 fish species. Detection of the disease, especially in the field, is critical to managing disease prevention and control programmes. Recombinase polymerase amplification (RPA) is an isothermal method with a very short amplification period and a single incubation temperature ranging from 37 to 42°C, which is a good alternative to the polymerase chain reaction (PCR). This study aimed to develop an RPA assay as sensitive as a real-time RT-PCR to detect VHSV. For this purpose, primers and probes are designed for the same targeted region of gG of VHSV. The ssRNA standards were prepared to find the detection limits of the assay. Detection limits were found ten-fold differences between real-time RT-PCR and real-time RT-RPA. While the detection limit of the RT-PCR was found as 95.5 viral RNA molecules/reaction in 95% probit value, the detection limit of RT-RPA was found as 943.75 viral RNA molecules/reaction in 95% probit value using ssRNA standards. These results show that RPA is a suitable test for VHSV Ie detection.

COVID-19 Pandemic Disruption on the Management of Tuberculosis Treatment in Indonesia

The current coronavirus disease 2019 (COVID-19) situation might deteriorate the efforts to eliminate tuberculosis (TB) in Indonesia. This study aimed to review the COVID-19 pandemic disruption on the management of TB treatment in Indonesia. We identified several disruptions due to the pandemic on TB control management. Firstly, there is a potential decrease in the funding for TB treatment. Financial disruptions caused by the COVID-19 pandemic have led to further setbacks. In many countries, including Indonesia, financial and other resources have been reallocated from TB to the COVID-19 response. Secondly, it has been highlighted that all TB services, including case detection and rapid diagnostic, have been disrupted by the pandemic. Thirdly, the pandemic would be associated with the lower quality of care and treatment for TB in Indonesia. It might decrease the enthusiasm of patients with TB, multi-drug resistant (MDR)-TB, and TB-human immunodeficiency virus (HIV) to visit TB hospitals because of social distancing measures by the government. Finally, the COVID-19 pandemic also has impacted critical activities of monitoring, evaluation, and surveillance. There are several lessons from other countries about managing TB treatment during the pandemic, such as combining screening for COVID-19 and TB by applying x-ray technology and artificial intelligence-based software. In addition, the use of telemedicine or telehealth in TB treatment is also beneficial to deliver medication, assess patients' progress, and inform prevention strategies. To reach the target with the end TB strategy, the government of Indonesia can adopt the World Health Organization's (WHO's) comprehensive strategies, such as integrated, patient-centered TB care and prevention strategies; bold policies and supportive systems; and intensified research and innovations.

Purpura with regular shape in an adolescent: Beware of dermatitis artefacta

BACKGROUND

Purpura is common in pediatric patients, mostly diagnosed as IgA-related vasculitis (Henoch-Schönlein purpura), idiopathic thrombocytopenic purpura (ITP), and thrombotic thrombocytopenic purpura (TTP). However, in some cases, for example, cases with dermatitis artefacta, it could puzzle a physician or pediatrician for a long time, with great challenges in diagnosis.

CASE PRESENTATION

We present the case of a 13-year-old boy with recurrent painful purpura on both upper limbs. The physical exam was unremarkable, except for right blepharoptosis and scars from burns. The diagnostic tests were normal. Through repeated communication, the patient was finally diagnosed as having dermatitis artefacta, accompanied by underlying psychological problems.

CONCLUSIONS

Before dermatitis artefacta was diagnosed, we spent a lot of money and effort on the diagnosis. Therefore, in order to determine the diagnosis as soon as possible and save on unnecessary medical expenses, we propose a rapid process for the diagnosis of purpura of dermatitis artefacta in children.

Rapid On-Site Detection of the Bursaphelenchus xylophilus Using Recombinase Polymerase Amplification Combined With Lateral Flow Dipstick That Eliminates Interference From Primer-Dependent Artifacts

The pine wood nematode (PWN), Bursaphelenchus xylophilus, is one of the most lethal nematode species, which causes pine wilt disease (PWD), a devastating forest disease. To date, no effective methods have been developed to control the disease; hence, rapid precise detection of B. xylophilus is of great significance. Traditional molecular diagnostic methods are time-consuming and require sophisticated instruments or skilled operators, which are unavailable in resource-limited settings. A specific, sensitive, and field-applicable diagnostic method is urgently needed. In this study, we developed a diagnostic method using recombinase polymerase amplification combined with lateral flow dipstick (RPA-LFD) for the rapid on-site detection of B. xylophilus. The false-positive signals from primer-dependent artifacts were eliminated using a probe, and base substitutions were included in the primer and probe. The entire detection process for the RPA-LFD assay can be completed under 38°C within approximately 30 min, including 15 min for crude nematode genomic DNA (gDNA) extraction and master mix preparation, 15 min for the RPA-LFD assay. This assay displayed high specificity toward B. xylophilus and showed no cross-reactions with closely related species, including Bursaphelenchus mucronatus and Bursaphelenchus doui. The sensitivity of this assay had a detection limit as low as 1 pg of B. xylophilus purified genomic DNA. Furthermore, the application of the RPA-LFD assay in simulated spiked pinewood samples showed accurate detection results. The RPA-LFD assay in this study successfully detected B. xylophilus in less than 30 min, providing a novel alternative for the simple, sensitive, and specific detection of B. xylophilus and showed potential for B. xylophilus point-of-care testing (POCT) in resource-limited areas or in field.

Development and Clinical Evaluation of a CRISPR-Based Diagnostic for Rapid Group B Streptococcus Screening

Vertical transmission of group B Streptococcus (GBS) is among the leading causes of neonatal illness and death. Colonization with GBS usually is screened weeks before delivery during pregnancy, on the basis of which preventive measures, such as antibiotic prophylaxis, were taken. However, the accuracy of such an antenatal screening strategy has been questionable because of the intermittent nature of GBS carriage. We developed a simple-to-use, rapid, CRISPR-based assay for GBS detection. We conducted studies in a prospective cohort of 412 pregnant women and a retrospective validation cohort to evaluate its diagnostic performance. We demonstrated that CRISPR-GBS is highly sensitive and offered shorter turnaround times and lower instrument demands than PCR-based assays. This novel GBS test exhibited an overall improved diagnostic performance over culture and PCR-based assays and represents a novel diagnostic for potential rapid, point-of-care GBS screening.

Randomized Trial Evaluating Clinical Impact of RAPid IDentification and Susceptibility Testing for Gram-negative Bacteremia: RAPIDS-GN

BACKGROUND

Rapid blood culture diagnostics are of unclear benefit for patients with gram-negative bacilli (GNB) bloodstream infections (BSIs). We conducted a multicenter, randomized, controlled trial comparing outcomes of patients with GNB BSIs who had blood culture testing with standard-of-care (SOC) culture and antimicrobial susceptibility testing (AST) vs rapid organism identification (ID) and phenotypic AST using the Accelerate Pheno System (RAPID).

METHODS

Patients with positive blood cultures with Gram stains showing GNB were randomized to SOC testing with antimicrobial stewardship (AS) review or RAPID with AS. The primary outcome was time to first antibiotic modification within 72 hours of randomization.

RESULTS

Of 500 randomized patients, 448 were included (226 SOC, 222 RAPID). Mean (standard deviation) time to results was faster for RAPID than SOC for organism ID (2.7 [1.2] vs 11.7 [10.5] hours; P < .001) and AST (13.5 [56] vs 44.9 [12.1] hours; P < .001). Median (interquartile range [IQR]) time to first antibiotic modification was faster in the RAPID arm vs the SOC arm for overall antibiotics (8.6 [2.6-27.6] vs 14.9 [3.3-41.1] hours; P = .02) and gram-negative antibiotics (17.3 [4.9-72] vs 42.1 [10.1-72] hours; P < .001). Median (IQR) time to antibiotic escalation was faster in the RAPID arm vs the SOC arm for antimicrobial-resistant BSIs (18.4 [5.8-72] vs 61.7 [30.4-72] hours; P = .01). There were no differences between the arms in patient outcomes.

CONCLUSIONS

Rapid organism ID and phenotypic AST led to faster changes in antibiotic therapy for gram-negative BSIs.

CLINICAL TRIALS REGISTRATION

NCT03218397.

Development and Validation of a Loop-Mediated Isothermal Amplification (LAMP) Assay for Rapid Detection of Glaesserella (Haemophilus) parasuis

Glaesserella parasuis is a fastidious pathogen that colonizes the respiratory tract of pigs and can lead to considerable economic losses in pig production. Therefore, a rapid detection assay for the pathogen, preferably applicable in the field, is important. In the current study, we developed a new and improved detection method using loop-mediated isothermal amplification (LAMP). This assay, which targets the infB gene, was tested on a collection of 60 field isolates of G. parasuis comprising 14 different serovars. In addition, 63 isolates from seven different closely related species of the family Pasteurellaceae, including A. indolicus, A. porcinus, and A. minor, and a species frequently found in the respiratory tract of pigs were used for exclusivity experiments. This assay showed an analytical specificity of 100% (both inclusivity and exclusivity) and an analytical sensitivity of 10 fg/µL. In further steps, 36 clinical samples were tested with the LAMP assay. An agreement of 77.1 (95% CI: 59.9, 89.6) and 91.4% (95% CI: 75.9, 98.2) to the culture-based and PCR results was achieved. The mean limit of detection for the spiked bronchoalveolar lavage fluid was 2.58 × 102 CFU/mL. A colorimetric assay with visual detection by the naked eye was tested to provide an alternative method in the field and showed the same sensitivity as the fluorescence-based LAMP assay. Overall, the optimized LAMP assay represents a fast and reliable method and is suitable for detecting G. parasuis in the laboratory environment or in the field.

Evaluation of a Rapid Fungal Detection Panel for Identification of Candidemia at an Academic Medical Center

This study was conducted to assess the utility of the T2Candida panel across an academic health center and identify potential areas for diagnostic optimization. A retrospective chart review was conducted on patients with a T2Candida panel and mycolytic/fungal (myco/f lytic) blood culture collected simultaneously during hospitalizations from February 2017 to March 2018. The primary outcome of this study was to determine the sensitivity, specificity, and positive and negative predictive values of the panel compared to myco/f lytic blood culture. Secondary outcomes included Candida species isolated from culture or detected on the panel, source of infection, days of therapy (DOT) of antifungals in patients with discordant results, and overall antifungal DOT/1,000 patient days. A total of 433 paired T2Candida panel and myco/f lytic blood cultures were identified. The pretest likelihood of candidemia was 4.4%. The sensitivity and specificity were 64.7% and 95.6%, respectively. The positive and negative predictive values were 40.7% and 98.5%, respectively. There were 16 patients with T2Candida panel positive and myco/f lytic blood culture negative results, while 6 patients had T2Candida panel negative and myco/f blood culture positive results. The overall antifungal DOT/1,000 patient days was improved after implementation of the T2Candida panel; however, the use of micafungin continued to decline after the panel was removed. We found that the T2Candida panel is a highly specific diagnostic tool; however, the sensitivity and positive predictive value may be lower than previously reported when employed in clinical practice. Clinicians should use this panel as an adjunct to blood cultures when making a definitive diagnosis of candidemia.

Improvement of the Immunochromatographic NG-Test Carba 5 Assay for the Detection of IMP Variants Previously Undetected

Here, we evaluated the immunochromatographic assay NG-Test Carba 5v2 (NG-Biotech), with improved IMP variant detection on 31 IMP producers, representing the different branches of the IMP phylogeny, including 32 OXA-48, 19 KPC, 12 VIM, 14 NDM, and 13 multiple carbapenemase producers (CPs), 13 CPs that were not targeted, and 13 carbapenemase-negative isolates. All tested IMP variants were accurately detected without impairing detection of the other carbapenemases. Thus, NG-Test Carba 5v2 is now well adapted to countries with high IMP prevalence and to the epidemiology of CP-Pseudomonas aeruginosa, where IMPs are most frequently detected.

A Healthcare Improvement Intervention Combining Nucleic Acid Microarray Testing With Direct Physician Response for Management of Staphylococcus aureus Bacteremia

Background

Nucleic acid microarray (NAM) testing for detection of Staphylococcus aureus bacteremia (SAB) and S. aureus resistance gene determinants can reduce time to targeted antibiotic administration. Evidence-based management of SAB includes bedside infectious diseases (ID) consultation. As a healthcare improvement initiative at our institution, with the goal of improving management and outcomes for subjects with SAB, we implemented NAM with a process for responding to positive NAM results by directly triggered, mandatory ID consultation.

Methods

Preintervention, SAB was identified by traditional culture and results passively directed to antibiotic stewardship program (ASP) pharmacists. Postintervention, SAB in adult inpatients was identified by Verigene Gram-Positive Blood Culture test, results paged directly to ID fellow physicians, and consultation initiated immediately. In the new process, ASP assisted with management after the initial consultation. A single-center, retrospective, pre-/postintervention analysis was performed.

Results

One hundred six preintervention and 120 postintervention subjects were assessed. Time to ID consultation after notification of a positive blood culture decreased 26.0 hours (95% confidence interval [CI], 45.1 to 7.1 hours, P < .001) postintervention compared with preintervention. Time to initiation of targeted antibiotic decreased by a mean of 21.2 hours (95% CI, 31.4 to 11.0 hours, P < .001) and time to targeted antibiotics for methicillin-sensitive S. aureus decreased by a mean of 40.7 hours (95% CI, 58.0 to 23.5 hours, P < .001). The intervention was associated with lower in-hospital (13.2% to 5.8%, P = .047) and 30-day (17.9% to 8.3%, P = .025) mortality.

Conclusions

Compared with an ASP-directed response to traditionally detected SAB, an efficient physician response to NAM was associated with improved care and outcomes for SAB.

Evaluation of the Immunochromatographic NG-Test Carba 5 for Rapid Identification of Carbapenemase in Nonfermenters

The immunochromatographic assay NG-Test Carba 5 (NG-Biotech) was evaluated with a collection of 107 carbapenemase-producing nonfermenters (CP-NF) (55 Pseudomonas spp., 51 Acinetobacter spp., and 1 Achromobacter xylosoxidans isolate) and 61 carbapenemase-negative isolates. All KPC, VIM, and NDM carbapenemase producers tested were accurately detected. Of the 16 IMP variants tested, 6 (37.5%) variants were not detected. Considering the epidemiology of CP-NFs in France, the NG-Test Carba 5 would detect 89.4% of CP Pseudomonas spp. but only 12.9% of CP Acinetobacter spp.

NG-Test Carba 5 for Rapid Detection of Carbapenemase-Producing Enterobacterales from Positive Blood Cultures

The immunochromatographic assay, NG-test Carba 5 (NG Biotech), has been evaluated for detection of carbapenemase-producing Enterobacterales (CPE) from spiked blood cultures (n = 205). It detected and discriminated in less than 30 minutes KPC, IMP, VIM, NDM, and OXA-48-like producers with a sensitivity and specificity of 97.7% and 96.1%, respectively. Thus, it might help the rapid optimization of treatment of bloodstream infections due to CPE.

The Basics and the Advancements in Diagnosis of Bacterial Lower Respiratory Tract Infections

Lower respiratory tract infections (LRTIs) are the leading infectious cause of death and the sixth-leading cause of death overall worldwide. Streptococcus pneumoniae, with more than 90 serotypes, remains the most common identified cause of community-acquired acute bacterial pneumonia. Antibiotics treat LRTIs with a bacterial etiology. With the potential for antibiotic-resistant bacteria, defining the etiology of the LRTI is imperative for appropriate patient treatment. C-reactive protein and procalcitonin are point-of-care tests that may differentiate bacterial versus viral etiologies of LRTIs. Major advancements are currently advancing the ability to make rapid diagnoses and identification of the bacterial etiology of LRTIs, which will continue to support antimicrobial stewardship, and is the focus of this review.

Tailoring Empirical Antimicrobial Therapy in Subjects With Ventilator-Associated Pneumonia With a 10-Hour E-Test Approach

BACKGROUND

In a previous study of subjects suspected of having ventilator-associated pneumonia, a rapid susceptibility testing approach by using ETEST (BioMérieux) strips directly applied to bronchoalveolar lavage samples provided valuable information at hour 24. The primary objective of this study was to assess a new direct specimen testing by using an even more-rapid E-test approach (at hour 10), which could promote an early de-escalation of the antimicrobial therapy.

METHODS

Twenty-eight subjects with ventilator-associated pneumonia admitted to a medical ICU were prospectively included. In parallel with standard routine methods, E-test strips were directly applied onto agar plates seeded with bronchoalveolar lavage samples and were analyzed after 10 h of incubation. E-test results were used to identify potential drug choices by simulating clinical decision making if the microscopy results had been available at the point of care. These choices were analyzed for concordance with the narrowest adequate antimicrobial therapy according to the Minimum Inhibitory Concentrations (MICs) provided by the reference method (ie, the laboratory routine diagnostic).

RESULTS

At hour 10, direct specimen testing was readable in 18 of 28 bronchoalveolar lavage samples (64%). Total agreement between the 10-h direct specimen testing approach and the laboratory routine diagnostic approach was 90%, with a sensitivity of 83% and a specificity of 95%, with 8% major errors and 3% very major errors. The concordance between the 2 tests was very good (kappa = 0.79). If the 10-h E-test results were taken into account, then an early de-escalation strategy would have been possible in 10 of 18 cases (55%) at hour 10.

CONCLUSIONS

This rapid susceptibility testing approach provided early (10 h) and valuable information that could lead to an early adjustment of empirical antimicrobial treatment in a ventilator-associated pneumonia setting. (ClinicalTrials.gov registration NCT01266863.).

Validation of an Antimicrobial Stewardship-Driven Verigene Blood-Culture Gram-Negative Treatment Algorithm to Improve Appropriateness of Antibiotics

Rapid diagnostic testing (RDT) allows for early adjustment of antibiotic therapy. This study examined the potential impact of a stewardship-driven antibiotic treatment algorithm, incorporating RDT into the management of Gram-negative bacteremia. The proposed algorithm would have resulted in 88.4% of cases receiving appropriate antibiotic therapy versus 78.1% by standard of care (P = .014).

Implementation and optimization of molecular rapid diagnostic tests for bloodstream infections

PURPOSE

The implementation and optimization of molecular rapid diagnostic tests (mRDTs) as an antimicrobial stewardship intervention for patients with bloodstream infections (BSIs) are reviewed.

SUMMARY

All U.S. acute care hospitals accredited by the Joint Commission are required to implement an antimicrobial stewardship program (ASP). Of the many interventions available to ASPs, mRDTs have demonstrated consistent, meaningful results on antimicrobial optimization and patient outcomes. Even among infectious diseases and antimicrobial stewardship-trained pharmacists, significant knowledge and familiarity gaps exist regarding available mRDTs and how best to implement and optimize them. Given the paucity of infectious diseases and/or antimicrobial stewardship-trained pharmacists, the mandates for establishing ASPs will require non-infectious diseases/antimicrobial stewardship-trained pharmacists to implement stewardship interventions, which may include mRDTs, within their institution. Optimization of mRDTs requires adequate diagnostic stewardship, specifically evaluating how mRDT implementation may decrease costs and assist in meeting antimicrobial stewardship regulatory requirements. Knowledge of how these technologies will augment existing microbiology and antimicrobial stewardship workflow is essential. Finally, selecting the right mRDT necessitates familiarity with the instrument's capabilities and with the institutional antibiogram.

CONCLUSION

mRDTs have demonstrated the ability to be one of the most powerful antimicrobial stewardship interventions. Pharmacists required to implement an ASP in their institution should consider mRDTs as standard of care for patients with BSIs.

An Antibiotic Stewardship Program Blueprint for Optimizing Verigene BC-GN within an Institution: a Tale of Two Cities

Rapid diagnostic tests (RDTs) have revolutionized the management of Gram-negative bacteremia by allowing antimicrobial stewardship teams the ability to escalate therapy and improve patient outcomes through timely organism identification and detection of certain resistance determinants. However, given the complex nature of Gram-negative resistance, stewardship teams are left without clear direction for how to respond when resistance determinants are absent, as the safety of de-escalation in this setting is unknown. The primary purpose of this analysis was to determine the negative predictive values (NPVs) of resistance marker absence for predicting susceptibility in target bug-drug scenarios at two geographically distinct institutions. A total of 1,046 Gram-negative bloodstream isolates that were analyzed with the Verigene BC-GN platform were assessed. Except for Pseudomonas aeruginosa, the absence of resistance determinants as reported by the RDT largely predicted susceptibility to target antibiotics at both institutions. NPVs for ceftriaxone susceptibility in Escherichia coli and Klebsiella pneumoniae in the absence of either CTX-M or a carbapenemase gene were 98% and 93 to 94%, respectively. Similar results were seen with other target bug-drug scenarios, with NPVs of 94 to 100% demonstrated at both institutions, with the exception of P. aeruginosa, for which NPVs were poor, likely due to the more complex nature of resistance in this pathogen. The results of this study show that clinicians at both institutions should have confidence in de-escalation in the absence of resistance determinant detection by Verigene BC-GN testing, and the methodology described within this article can serve as a blueprint for other stewardship programs to employ at their institutions to optimize management of Gram-negative bacteremia.

Stewardship opportunities in viral pneumonia: Why not the immunocompromised?

Antimicrobial management of viral pneumonia has proven to be a challenge in hospitalized immunocompromised patients. A host of factors contribute to the dilemma, such as diagnostic uncertainty, lack of organism identification, and clinical status of the patient. Respiratory virus panel (RVP) use was compared between 131 immunocompromised patients who received send‐out (n = 56) vs in‐house (n = 75) testing. Antimicrobial optimization interventions consisted of antiviral addition/discontinuation, antibiotic discontinuation/de‐escalation, or modification of immunosuppressive regimen. After implementation of an in‐house test with audit and feedback, turnaround time of the RVP was reduced from 46.7 to 5.5 hours (P < .001) and time to intervention was reduced from 52.1 to 13.9 hours (P < .001), yet the frequency of antimicrobial optimization interventions was unchanged (30.7% vs 35.7%). Differences were not observed in duration of empiric antibiotic therapy or length of stay. The overall discontinuation rate for patients tested with a RVP was low (4.6%), and those with positive RVP (n = 43) had antibiotics stopped in 14% of cases. Bacterial pneumonia coinfection was confirmed in 2 patients. Further systematic efforts should be taken to reduce antibiotic use in viral pneumonia and identify the major barriers in the immunocompromised population.

Hemozoin detection may provide an inexpensive, sensitive, 1-minute malaria test that could revolutionize malaria screening

Malaria remains widespread throughout the tropics and is a burden to the estimated 3.5 billion people who are exposed annually. The lack of a fast and accurate diagnostic method contributes to preventable malaria deaths and its continued transmission. In many areas diagnosis is made solely based on clinical presentation. Current methods for malaria diagnosis take more than 20 minutes from the time blood is drawn and are frequently inaccurate. The introduction of an accurate malaria diagnostic that can provide a result in less than 1 minute would allow for widespread screening and treatment of endemic populations, and enable regions that have gained a foothold against malaria to prevent its return. Using malaria parasites' waste product, hemozoin, as a biomarker for the presence of malaria could be the tool needed to develop this rapid test.

Significant roadblocks exist in developing sputum sample libraries for clinical validation of novel in vitro diagnostics

With the continuing rise of multiresistant pathogens, reliable, cost-effective, and novel diagnostics are urgently required by clinicians and clinical trialists to diagnose conditions such as respiratory tract infections to enable rational antimicrobial choice and enhance clinical outcomes. However, during product development, validation of these in vitro diagnostic devices, a key regulatory hurdle, requires sputum samples in large numbers. The Rapid Point-of-Care test Platform for Infectious Diseases (RAPP-ID) consortium is tasked with producing point of care test (POCT) platforms for rapid diagnosis of lower respiratory tract infections, including tuberculosis and blood stream infections. Validation of diagnostic platforms would ideally use well-characterized samples in a sputum library taken from a range of clinical settings to allow for a wide panel of pathogens to be assessed. These samples would be stored in specific stable conditions (monitored temperature, specific medium) until required for validation. Therefore we reviewed the current literature for details of storage conditions of sputum samples and for previous validation studies of other diagnostic tests using this methodology. However, we conclude that little data exists, and thus the acquisition and successful storage of good quality clinical samples are major roadblocks in the validation of novel POCT platforms, and that while not without limitations, spiked sputum samples appear the best solution until sputum library laboratory techniques allowing careful preservation of pathogens are improved.

Rapid, low-cost fluorescent assay of β-lactamase-derived antibiotic resistance and related antibiotic susceptibility

Antibiotic resistance (AR) is increasingly prevalent in low and middle income countries (LMICs), but the extent of the problem is poorly understood. This lack of knowledge is a critical deficiency, leaving local health authorities essentially blind to AR outbreaks and crippling their ability to provide effective treatment guidelines. The crux of the problem is the lack of microbiology laboratory capacity available in LMICs. To address this unmet need, we demonstrate a rapid and simple test of β -lactamase resistance (the most common form of AR) that uses a modified β -lactam structure decorated with two fluorophores quenched due to their close proximity. When the β -lactam core is cleaved by β -lactamase, the fluorophores dequench, allowing assay speeds of 20 min to be obtained with a simple, streamlined protocol. Furthermore, by testing in competition with antibiotics, the β -lactamase-associated antibiotic susceptibility can also be extracted. This assay can be easily implemented into standard lab work flows to provide near real-time information of β -lactamase resistance, both for epidemiological purposes as well as individualized patient care.